package com.wolf.gulimall.cart.interceptor;


import com.wolf.common.constant.AuthServerConstant;
import com.wolf.common.constant.CartConstant;
import com.wolf.common.vo.MemberEntityVo;
import com.wolf.gulimall.cart.to.UserInfoTo;
import org.apache.commons.lang.StringUtils;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * 拦截器:在执行目标方法之前,判断用户是否登录,并封装返回给controller目标请求
 */
public class CartInterceptor implements HandlerInterceptor {


    //线程共享变量(同一个线程内部)
    public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

    /**
     * 在目标分方法执行之前拦截
     *
     * @param request  请求
     * @param response 响应
     * @param handler  拦截处理
     * @return 拦截处理后的结果
     * @throws Exception 异常
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        UserInfoTo userInfoTo = new UserInfoTo();
        HttpSession session = request.getSession();
        MemberEntityVo memberEntityVo = (MemberEntityVo) session.getAttribute(AuthServerConstant.LOGIN_USER);
        if (memberEntityVo != null) {
            //用户已经登录,设置用户ID
            userInfoTo.setUserId(memberEntityVo.getId());
        }
        Cookie[] cookies = request.getCookies();
        if (cookies != null && cookies.length > 0) {
            for (Cookie cookie : cookies) {
                //获取cookie中 的唯一标识 user-key
                String name = cookie.getName();
                if(name.equals(CartConstant.TEMP_USER_COOKIE_NAME)){
                    userInfoTo.setUserKey(cookie.getValue());
                    userInfoTo.setTempUser(true);
                }
            }
        }

        //如果没有临时用户一定分配一个临时用户
        if(StringUtils.isEmpty(userInfoTo.getUserKey())){
            String uuid = UUID.randomUUID().toString();
            userInfoTo.setUserKey(uuid);
            userInfoTo.setTempUser(true);
        }

        //将用户信息放入到本地线程变量中,以便后续操作获取当前封装的数据
        threadLocal.set(userInfoTo);
        return true;
    }

    /**
     *  业务执行之后进行拦截处理,创建一个临时用户,让浏览器保存
     * @param request 请求
     * @param response 响应
     * @param handler 拦截处理器
     * @param modelAndView 模型视图
     * @throws Exception 异常
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        UserInfoTo userInfoTo = threadLocal.get();
        if(userInfoTo.isTempUser()){
            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME,userInfoTo.getUserKey());
            cookie.setDomain("gulimallwolf.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIME_OUT);
            response.addCookie(cookie);
        }

    }
}
